Organ

Does The Brain Age Faster Than The Liver? Different Organs Age At Different Rates

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A new animal study suggests aging is not a gradual decline of the entire body all at once, but a more disordered process with some organs deteriorating faster than others. How each individual organ ages depends on its cellular proteins and its physiological function in the body, new research from the Salk Institute for Biological Studies proposes.

“Aging is associated with the decline of protein, cell, and organ function,” wrote the authors in their study. “We identify 468 differences in protein abundance between young and old animals.”

Aging, in clinical terms, is a progressive deterioration of organ function as the cells and proteins within organs decline. Meanwhile, the activity levels of genes decrease as animals grow older, past studies have shown, with most genes showing similar changes across all organs. However, a recent study using state of the art technologies on mice tissue concluded the vast majority of proteins remain unchanged in number with age. These recent findings made the issue of age more confusing.

How exactly does aging affect proteins, then, if it doesn’t decrease their numbers? the scientists wondered. Do age-related changes differ from organ to organ?

The Brain vs. the Liver

Co-first authors of the study, Dr. Brandon Toyama of the Salk Institute and Dr. Alessandro Ori of the European Molecular Biology Laboratory combined genomics and proteomics in their examination of young and old rats. By focusing on both genes and proteins at once, these two researchers and their colleagues were better able to analyze cellular changes in the animals’ livers and brains. What did they discover?

First, they were able to identify 468 differences in protein abundance between the young and old animals. Second, they observed another set of 130 proteins showing age-related differences in terms of their location within cells, their phosphorylation state, or some other characteristic that would affect either the activity level or function of proteins.

Essentially, then, these discoveries expanded the list of (mammal) proteins modified by age.

The scientists most dramatic finding? Most of the age-related differences in proteins could be found in just one organ or another, with the brain aging faster than the liver. In fact, a larger proportion of proteins in the brain were affected by aging compared to the liver. The reason why, the researchers theorized, is because cells in each of these organs function uniquely. Throughout adulthood, for instance, cells in the liver are frequently replaced. By contrast, neurons in the brain are non-dividing and must survive for the entire lifetime. And so they feel the effects of aging most.

Based on their new findings, the researchers define aging as an organ-specific deterioration of the cellular proteome. Going forward, they plan to study differences between individuals, nevertheless, the researchers believe this current work provides “a rich data resource to stimulate further studies of aging.”

First double leg-transplant patient has legs amputated.

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The world’s first double leg-transplant patient has had his legs amputated, a Spanish hospital has confirmed.

The amputation was carried out after an unrelated illness forced the man to stop taking anti-rejection drugs, according to Valencia‘s Hospital La Fe.

The hospital said treatment of the unspecified illness was “more urgent”.

The transplant was carried out in July 2011 by surgeon Pedro Cavadas, who also led a team that carried out the first double hand transplant in 2006.

The man who received the double leg transplant, who was in his 20s at the time and has not been named, initially lost his legs above the knee in a road accident.

‘Vital organ’

Mr Cavadas and his team of more than 50 at Hospital La Fe took more than 10 hours to attach the new legs, a procedure that included connecting nerves, blood vessels, muscles, tendons and bone structure.

The patient was expected to take immuno-suppressant drugs for the rest of his life, but had to stop because the medicine was complicating the treatment of an illness he contracted, doctors said.

“In these cases the protocol is that, if the transplanted organ is not a vital organ, it should be removed from the patient so as to allow treatment of the illness that is more serious and urgent,” the hospital said in a statement.

Mr Cavadas is referred to as a “miracle doctor” by parts of the Spanish media for his pioneering procedures.

Source: BBC

 

Organs Wasted in Kidney Transplant Network .

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The current system of allocating kidneys is flawed, with organs being discarded that might otherwise have benefited people — and the problem is growing — the New York Times reports.

The paper says that in 2011, some 2600 of 15,000 kidneys recovered for transplantation were discarded — many because recipients could not be found in time (the article notes that “it is not precisely clear” how many discarded kidneys might actually have been useful). The number of kidneys discarded has grown over 75% in the past decade, “more than twice as fast as the increase in kidney recoveries,” according to the Times.

Federal efforts to monitor the quality of transplantation programs may also inadvertently contribute to the problem. The effort to keep success rates high has made transplant surgeons “far more selective about the organs and patients they accepted, leading to more discards.”

New proposals for kidney allocation have been put forward, but remain similar to the system already in place.

Source:New York Times